Vehicular driver assist system

ABSTRACT

A vehicular driver assistance system includes a camera disposed at a vehicle and a control having an image processor that processes image data captured by the camera to determine lane markings demarcating a traffic lane in which the vehicle is traveling and to estimate a path of travel for the vehicle to maintain the vehicle in the traffic lane in which the vehicle is traveling in situations where the lane markings demarcating the traffic lane in which the vehicle is traveling are not readily determinable. The control estimates the path of travel for the vehicle at least responsive to vehicle information. The system updates the estimated path of travel ahead of the vehicle even when no lane markings are determined present on the road ahead of the vehicle. The control adjusts processing of captured image data responsive at least in part to a driving situation that the vehicle is in.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/446,221, filed Mar. 1, 2017, now U.S. Pat. No. 10,055,651,which claims the filing benefits of U.S. provisional application Ser.No. 62/305,216, filed Mar. 8, 2016, which is hereby incorporated hereinby reference in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to a vehicle vision system for avehicle and, more particularly, to a vehicle vision system that utilizesone or more cameras at a vehicle.

BACKGROUND OF THE INVENTION

Use of imaging sensors in vehicle imaging systems is common and known.Examples of such known systems are described in U.S. Pat. Nos.5,949,331; 5,670,935 and/or 5,550,677, which are hereby incorporatedherein by reference in their entireties.

SUMMARY OF THE INVENTION

The present invention provides a driver assistance system or visionsystem or imaging system for a vehicle that utilizes one or more cameras(preferably one or more CMOS cameras) to capture image datarepresentative of images exterior of the vehicle, and provides enhancedtracking of lanes along the road on which the vehicle is tracking, suchas in situations where the camera loses the lane markings and/or tendsto track the wrong lane markings and/or the like. The system utilizesadditional inputs, such as vehicle inputs and geographical locationinputs (such as GPS data and digital map data and the like) to enhancetracking and estimation of the lane along which the vehicle is travelingeven in situations where the lane markers are not readily determinableby the camera and image processing.

The system of the present invention thus creates an abstraction layerbetween the image processing and the feature that would use the path(such as automated driving or the like). With the system of the presentinvention, the lane marker data from image processing of captured imagedata becomes one of the inputs to the new abstraction layer, rather thanthe sole supplier of path information. That image processing based inputis combined with map data, GPS positioning data or information,differential wheel speeds, and/or the like, to determine where thedesired path is ahead of the vehicle when the image-based determinationsare not sufficient.

These and other objects, advantages, purposes and features of thepresent invention will become apparent upon review of the followingspecification in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a vehicle with a vision system thatincorporates cameras in accordance with the present invention;

FIG. 2 is an image showing a use case where the camera loses the lanemarkings for a short period of time;

FIG. 3 is an image showing a use case where the camera loses the lanemarkings for a short period of time at intersections;

FIG. 4 is an image showing a use case where the camera may erroneouslydetermine lane curvature;

FIG. 5 is an image showing a use case where the camera may track thewrong lane markers, such as by tracking an exit lane instead of thecorrect road lane markers;

FIG. 6 is a block diagram of the system structure overview of thepresent invention;

FIG. 7 is a schematic showing the data preprocessing of the system ofthe present invention;

FIG. 8 is a schematic showing the fusion functions of the system of thepresent invention;

FIG. 9 is a schematic showing the process for determining the left laneand the right lane in accordance with the present invention;

FIGS. 10-15 show application of the present invention to the first usecase of FIG. 2;

FIGS. 16-26 show application of the present invention to the second usecase of FIG. 3;

FIGS. 27-29 show application of the present invention to the third usecase of FIG. 4; and

FIGS. 30-32 show application of the present invention to the fourth usecase of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A vehicle vision system and/or driver assist system and/or objectdetection system and/or alert system operates to capture images exteriorof the vehicle and may process the captured image data to display imagesand to detect objects at or near the vehicle and in the predicted pathof the vehicle, such as to assist a driver of the vehicle in maneuveringthe vehicle in a rearward direction. The vision system includes an imageprocessor or image processing system that is operable to receive imagedata from one or more cameras and provide an output to a display devicefor displaying images representative of the captured image data.Optionally, the vision system may provide display, such as a rearviewdisplay or a top down or bird's eye or surround view display or thelike.

Referring now to the drawings and the illustrative embodiments depictedtherein, a vehicle 10 includes an imaging system or vision system 12that includes at least one exterior facing imaging sensor or camera,such as a forward facing imaging sensor or camera 14 a at a frontportion of the vehicle or at and behind the windshield of the vehicleand viewing through the windshield, which captures images exterior andforward of the vehicle, with the camera having a lens for focusingimages at or onto an imaging array or imaging plane or imager of thecamera (FIG. 1). Optionally, the system may include multiple exteriorfacing imaging sensors or cameras, such as a rearwardly facing camera 14b at the rear of the vehicle, and a sidewardly/rearwardly facing camera14 c, 14 d at respective sides of the vehicle, which capture imagesexterior of the vehicle. The forward viewing camera may be disposed atthe windshield of the vehicle and view through the windshield andforward of the vehicle, such as for a machine vision system (such as fortraffic sign recognition, headlamp control, pedestrian detection,collision avoidance, lane marker detection and/or the like). The visionsystem 12 includes a control or electronic control unit (ECU) orprocessor 18 that is operable to process image data captured by thecamera or cameras and may detect objects or the like and/or providedisplayed images at a display device 16 for viewing by the driver of thevehicle (although shown in FIG. 1 as being part of or incorporated in orat an interior rearview mirror assembly 20 of the vehicle, the controland/or the display device may be disposed elsewhere at or in thevehicle). The data transfer or signal communication from the camera tothe ECU may comprise any suitable data or communication link, such as avehicle network bus or the like of the equipped vehicle.

Lane information determined from image data captured by a forwardviewing camera is erroneous in some situations. The camera informationcan be corrected by using an independent data source. By means of fusionof lane information from the camera and from a digital map, the qualityof lane information can be improved. This function can be utilized bymultiple ADAS features, such as, for example, Automated Driving and/orthe like.

The present invention provides enhanced lane tracking in situationswhere the lane markers may not be present or where the lane markers arenot readily detectable by processing of captured image data (such aswhen the view of the lane markings by the camera is obstructed, such asdue to another vehicle or object on the road or due to a curvature inthe road or undulation in the road or the like). The system of thepresent invention defines use cases and collects test data, such asvideo clips and CAN recording of camera outputs, vehicle chassis CAN,GPS position and the like. The system checks test data for use cases anddevelops functions to improve path reckoning performance in defined usecases where lane marking detection becomes unreliable, such as byreplaying recorded CAN data in simulation. Thus, when the systemdetermines that the vehicle is currently in one of the defined usecases, the system may adjust the path estimation process to adapt to thecurrent condition or situation, thus providing enhanced path estimationin various conditions or types of situations that are typicallyencountered by a vehicle on the road. Testing has shown that the systemfunctions in simulation and in test drives in Germany and USA.

Some exemplary use cases are shown in FIGS. 2-5 and include cases wherethe camera loses the lane markings for a few seconds (FIG. 2), where thecamera loses lane markings at intersections (FIG. 3), where the systemerroneously estimates the lane curvature (FIG. 4), and where the cameratracks an exit lane instead of the correct lane marking (FIG. 5).

The system structure overview is shown in FIG. 6, and the datapreprocessing of the system is shown in FIG. 7. In the datapreprocessing, a map database (such as ADASRP or the like) provideselectronic horizon for configurable preview distance (such as, forexample, about one kilometer or thereabouts). For this preview distance,attribute values (such as, for example, the radius of the road ahead ofthe subject vehicle) are provided along with the distance to the currentsubject vehicle position. The distance values are updated at 1 Hz rate,and additional attribute values are transmitted when the previewdistance falls below a desired value. The fusion functions of the systemare shown in FIG. 8, and the process for determining the left lane andthe right lane is shown in FIG. 9.

FIGS. 10-15 show application of the present invention to the first usecase (FIG. 2), where the camera loses the lane markings for a fewseconds. When such loss of lane markings occurs, the system predicts thelane heading responsive to a digital map, the latest heading from thecamera before the loss, with changes calculated such as shown in FIGS.12 and 13.

FIGS. 16-26 show application of the present invention to the second usecase (FIG. 3), where the camera loses the lane markings atintersections. An enhanced dropout compensation algorithm has beendeveloped based on use case 1 in order to compensate dropouts atintersections. The system and algorithm provide more accurate headingangle by using additional sensor data which are fused such as by meansof an Extended Kalman Filter (EKF). The algorithm and heading angleestimation calculations are shown in FIGS. 16-18, and the results oftest and parameterize algorithms in intersection scenarios are shown inFIGS. 19-26.

FIGS. 27-29 show application of the present invention to the third usecase (FIG. 4), where the system erroneously estimates the lanecurvature. The algorithm (see FIG. 27) determines whether or not to usethe determined left and/or right curvatures to estimate the path oftravel for the vehicle to maintain the vehicle in the lane it wastraveling along.

FIGS. 30-32 show application of the present invention to the fourth usecase (FIG. 5), where the camera tracks an exit lane instead of thecorrect lane marking. The algorithm (see FIG. 30) uses map data todetermine distances (from the vehicle's current geographical location)to intersections or road crossings and determines whether or not adetermined lane marking may be an exit lane marking to estimate the pathof travel for the vehicle to maintain the vehicle in the lane it wastraveling along.

Thus, the present invention provides enhanced tracking or estimation oflanes of the road on which the vehicle is traveling for situations wherethe camera or system loses the lane markings or may track the wrong lanemarkings. The system provides compensation of camera errors andincreases the availability of automated driving functions (such as, forexample, lane keeping or the like). The compensation of camera errorsrequires a map data base that has to be available in the vehicle. Thealgorithms to compensate for camera dropouts are not complex and thusthe system of the present invention does not require high processingpower. The system may utilize camera and navigation fusion functions,which may be implemented in the camera ECU or at a control unit of thevehicle that is separate from the camera (and that may communicate withthe camera via a communication bus of the vehicle). The system mayutilize a sensor CAN bus and a vehicle CAN bus, and may use inputs suchas vehicle velocity and yaw rate and position and heading informationand the like, along with GPS information pertaining to the vehiclelocation and the road along which the vehicle is traveling.

Therefore, the present invention provides a system that resolves someissues with lane data received from the image processing system, wherethere are situations like cresting a hill, crossing an intersection,passing entrance/exit ramps, or just unique situations where vehiclesline up oddly with the lane markings and the image processing system mayreport bad data. For lane keeping (nudging at the marking) andparticularly for lane centering (always active), it is important to havea good model of the path ahead. The system of the present invention thuscreates an abstraction layer between the image processing and thefeature that would use the path (such as automated driving or adaptivecruise control or the like). With the system of the present invention,the lane data from the image processing becomes one of the inputs to thenew abstraction layer, rather than the sole supplier of pathinformation. That input is combined with map data, GPS positioning dataor information, differential wheel speeds, and/or the like, to determinewhere the desired path is ahead of the vehicle (even when lane markingsare not present or are difficult to discern via image processing ofcaptured image data). The vehicle is allowed to maneuver about thispredicted or estimated path of travel and the path will updateindependently of the vehicle “virtually under the vehicle,” even when nolane marking data is present ahead of the vehicle or discernible by thecamera and image processing.

The present invention provides an abstraction layer that has the imageprocessing lane output as one of the inputs. It also takes inputs frommap data, GPS positioning, yaw rate, steering angle and differentialwheel speeds (preferably non-driven wheels, but even 4wd vehicles can betaken into consideration). The system may determine objects on the roadplane that obstruct the path. All of this is fused together to make apath reckoning system. The output of such a system provides an enhancedmodel of the path ahead of the subject vehicle. The system of thepresent invention is not a typical dead reckoning system that tries tomaintain the vehicle's trajectory when the sensor data drops out.Instead, the present invention creates a path for the vehicle usingmultiple inputs that may drop out. The vehicle can move about on thispath and the control system will still react to the path boundaries,even if there are no lane markings. Testing has found the system to beaccurate to within about 10 cm of the actual lane markings aftertraveling as much as 100 meters. As shown in the drawings, FIGS. 20 and22, bottom left graph, the lane data drop out is bounded between thevertical bars (at around 40 and 43 in FIG. 20 and at around 63.6 and69.4 in FIG. 22). As the vehicle approaches the far side the lanemarkings come back and the error is about 0.1 m (which is about thewidth of a lane marking).

The camera or sensor may comprise any suitable camera or sensor.Optionally, the camera may comprise a “smart camera” that includes theimaging sensor array and associated circuitry and image processingcircuitry and electrical connectors and the like as part of a cameramodule, such as by utilizing aspects of the vision systems described inInternational Publication Nos. WO 2013/081984 and/or WO 2013/081985,which are hereby incorporated herein by reference in their entireties.

The system includes an image processor operable to process image datacaptured by the camera or cameras, such as for detecting objects orother vehicles or pedestrians or the like in the field of view of one ormore of the cameras. For example, the image processor may comprise animage processing chip such as a chip of the EyeQ family of imageprocessing chips available from Mobileye Vision Technologies Ltd. ofJerusalem, Israel, and may include object detection software (such asthe types described in U.S. Pat. Nos. 7,855,755; 7,720,580 and/or7,038,577, which are hereby incorporated herein by reference in theirentireties), and may analyze image data to detect vehicles and/or otherobjects. Responsive to such image processing, and when an object orother vehicle is detected, the system may generate an alert to thedriver of the vehicle and/or may generate an overlay at the displayedimage to highlight or enhance display of the detected object or vehicle,in order to enhance the driver's awareness of the detected object orvehicle or hazardous condition during a driving maneuver of the equippedvehicle.

The vehicle may include any type of sensor or sensors, such as imagingsensors or radar sensors or lidar sensors or ladar sensors or ultrasonicsensors or the like. The system may also communicate with other systems,such as via a vehicle-to-vehicle communication system or avehicle-to-infrastructure communication system or the like. Such car2caror vehicle to vehicle (V2V) and vehicle-to-infrastructure (car2X or V2Xor V2I or 4G or 5G) technology provides for communication betweenvehicles and/or infrastructure based on information provided by one ormore vehicles and/or information provided by a remote server or thelike. Such vehicle communication systems may utilize aspects of thesystems described in U.S. Pat. Nos. 6,690,268; 6,693,517 and/or7,580,795, and/or U.S. Publication Nos. US-2014-0375476;US-2014-0218529; US-2013-0222592; US-2012-0218412; US-2012-0062743;US-2015-0251599; US-2015-0158499; US-2015-0124096; US-2015-0352953;US-2016-0036917 and/or US-2016-0210853, which are hereby incorporatedherein by reference in their entireties.

The imaging sensor or camera may capture image data for image processingand may comprise any suitable camera or sensing device, such as, forexample, a two dimensional array of a plurality of photosensor elementsarranged in at least 640 columns and 480 rows (at least a 640×480imaging array, such as a megapixel imaging array or the like), with arespective lens focusing images onto respective portions of the array.The photosensor array may comprise a plurality of photosensor elementsarranged in a photosensor array having rows and columns. Preferably, theimaging array has at least 300,000 photosensor elements or pixels, morepreferably at least 500,000 photosensor elements or pixels and morepreferably at least 1 million photosensor elements or pixels. Theimaging array may capture color image data, such as via spectralfiltering at the array, such as via an RGB (red, green and blue) filteror via a red/red complement filter or such as via an RCC (red, clear,clear) filter or the like. The logic and control circuit of the imagingsensor may function in any known manner, and the image processing andalgorithmic processing may comprise any suitable means for processingthe images and/or image data.

For example, the vision system and/or processing and/or camera and/orcircuitry may utilize aspects described in U.S. Pat. Nos. 9,233,641;9,146,898; 9,174,574; 9,090,234; 9,077,098; 8,818,042; 8,886,401;9,077,962; 9,068,390; 9,140,789; 9,092,986; 9,205,776; 8,917,169;8,694,224; 7,005,974; 5,760,962; 5,877,897; 5,796,094; 5,949,331;6,222,447; 6,302,545; 6,396,397; 6,498,620; 6,523,964; 6,611,202;6,201,642; 6,690,268; 6,717,610; 6,757,109; 6,802,617; 6,806,452;6,822,563; 6,891,563; 6,946,978; 7,859,565; 5,550,677; 5,670,935;6,636,258; 7,145,519; 7,161,616; 7,230,640; 7,248,283; 7,295,229;7,301,466; 7,592,928; 7,881,496; 7,720,580; 7,038,577; 6,882,287;5,929,786 and/or 5,786,772, and/or U.S. Publication Nos. 2014/0340510;2014/0313339; 2014/0347486; 2014/0320658; 2014/0336876; 2014/0307095;2014/0327774; 2014/0327772; 2014/0320636; 2014/0293057; 2014/0309884;2014/0226012; 2014/0293042; 2014/0218535; 2014/0218535; 2014/0247354;2014/0247355; 2014/0247352; 2014/0232869; 2014/0218529; 2014/0211009;2014/0160276; 2014/0168437; 2014/0168415; 2014/0160291; 2014/0152825;2014/0139676; 2014/0138140; 2014/0104426; 2014/0098229; 2014/0085472;2014/0067206; 2014/0049646; 2014/0052340; 2014/0025240; 2014/0028852;2014/005907; 2013/0314503; 2013/0298866; 2013/0222593; 2013/0300869;2013/0278769; 2013/0258077; 2013/0258077; 2013/0242099; 2013/0222592;2013/0215271; 2013/0141578 and/or 2013/0002873, which are all herebyincorporated herein by reference in their entireties.

Optionally, the vision system may include a display for displayingimages captured by one or more of the imaging sensors for viewing by thedriver of the vehicle while the driver is normally operating thevehicle. Optionally, for example, the vision system may include a videodisplay device, such as by utilizing aspects of the video displaysystems described in U.S. Pat. Nos. 5,530,240; 6,329,925; 7,855,755;7,626,749; 7,581,859; 7,446,650; 7,338,177; 7,274,501; 7,255,451;7,195,381; 7,184,190; 5,668,663; 5,724,187; 6,690,268; 7,370,983;7,329,013; 7,308,341; 7,289,037; 7,249,860; 7,004,593; 4,546,551;5,699,044; 4,953,305; 5,576,687; 5,632,092; 5,677,851; 5,708,410;5,737,226; 5,802,727; 5,878,370; 6,087,953; 6,173,508; 6,222,460;6,513,252 and/or 6,642,851, and/or U.S. Publication Nos.US-2012-0162427; US-2006-0050018 and/or US-2006-0061008, which are allhereby incorporated herein by reference in their entireties. Optionally,the vision system (utilizing the forward facing camera and a rearwardfacing camera and other cameras disposed at the vehicle with exteriorfields of view) may be part of or may provide a display of a top-downview or birds-eye view system of the vehicle or a surround view at thevehicle, such as by utilizing aspects of the vision systems described inInternational Publication Nos. WO 2010/099416; WO 2011/028686; WO2012/075250; WO 2013/019795; WO 2012/075250; WO 2012/145822; WO2013/081985; WO 2013/086249 and/or WO 2013/109869, and/or U.S.Publication No. US-2012-0162427, which are hereby incorporated herein byreference in their entireties.

Changes and modifications in the specifically described embodiments canbe carried out without departing from the principles of the invention,which is intended to be limited only by the scope of the appendedclaims, as interpreted according to the principles of patent lawincluding the doctrine of equivalents.

The invention claimed is:
 1. A driver assistance system for a vehicle,said driver assistance system comprising: a camera disposed at a vehicleand having a field of view forward of the vehicle; a control comprisingan image processor that is operable to process image data captured bysaid camera; wherein, responsive to processing by said image processorof image data captured by said camera, said control determines lanemarkings demarcating a traffic lane in which the vehicle is traveling;wherein, responsive to processing by said image processor of image datacaptured by said camera and responsive to a location input from a globalpositioning system to said control, said control estimates a path oftravel for the vehicle to maintain the vehicle in the traffic lane inwhich the vehicle is traveling in situations where the lane markingsdemarcating the traffic lane in which the vehicle is traveling are notreadily determinable; wherein said control estimates the path of travelfor the vehicle at least responsive to vehicle information, and whereinthe vehicle information comprises at least one selected from the groupconsisting of (i) vehicle speed, (ii) vehicle differential wheel speedsand (iii) vehicle yaw rate; wherein said driver assistance systemupdates the estimated path of travel ahead of the vehicle even when nolane markings are determined present on the road ahead of the vehicle;wherein said control adjusts processing by said image processor of imagedata captured by said camera responsive at least in part to a drivingsituation that the vehicle is in; and wherein the driving situationcomprises at least one driving situation selected from the groupconsisting of (i) the vehicle cresting a hill, (ii) the vehicle crossingan intersection, (iii) the vehicle passing an entrance ramp and (iv) thevehicle passing an exit ramp.
 2. The driver assistance system of claim1, wherein, responsive to processing by said image processor of imagedata captured by said camera, said control estimates the path of travelfor the vehicle to maintain the vehicle in the traffic lane in which thevehicle is traveling in situations where the lane markings demarcatingthe traffic lane in which the vehicle is traveling are lost by saidcamera for a period of time.
 3. The driver assistance system of claim 1,wherein, responsive to processing by said image processor of image datacaptured by said camera, said control estimates the path of travel forthe vehicle to maintain the vehicle in the traffic lane in which thevehicle is traveling in situations where the lane markings demarcatingthe traffic lane in which the vehicle is traveling are lost by saidcamera as the vehicle crosses an intersection.
 4. The driver assistancesystem of claim 1, wherein, responsive to processing by said imageprocessor of image data captured by said camera, said control estimatesthe path of travel for the vehicle to maintain the vehicle in thetraffic lane in which the vehicle is traveling in situations where lanemarkings are erroneously determined by processing by said imageprocessor of captured image data alone.
 5. The driver assistance systemof claim 1, wherein, responsive to processing by said image processor ofimage data captured by said camera, said control estimates the path oftravel for the vehicle to maintain the vehicle in the traffic lane inwhich the vehicle is traveling in situations where processing by saidimage processor of image data alone determines lane markings that arenot demarcating the traffic lane in which the vehicle is traveling. 6.The driver assistance system of claim 1, wherein said control estimatesthe path of travel for the vehicle at least in part responsive to alocation input from a global positioning system to said control thatprovides the vehicle's current geographical location information.
 7. Thedriver assistance system of claim 1, wherein said control estimates thepath of travel for the vehicle at least in part responsive to a mapinput from a digital map to said control that provides road informationpertaining to the road along which the vehicle is traveling.
 8. Thedriver assistance system of claim 1, wherein, responsive to processingby said image processor of image data captured by said camera andresponsive to a map input from a digital map to said control, saidcontrol estimates the path of travel for the vehicle to maintain thevehicle in the traffic lane in which the vehicle is traveling insituations where the lane markings demarcating the traffic lane in whichthe vehicle is traveling are not readily determinable.
 9. A driverassistance system for a vehicle, said driver assistance systemcomprising: a camera disposed at a vehicle and having a field of viewforward of the vehicle; a control comprising an image processor that isoperable to process image data captured by said camera; wherein,responsive to processing by said image processor of image data capturedby said camera, said control determines lane markings demarcating atraffic lane in which the vehicle is traveling; wherein, responsive toprocessing by said image processor of image data captured by said cameraand responsive to at least one input selected from the group consistingof (i) a map input from a digital map to said control and (ii) alocation input from a global positioning system to said control, saidcontrol estimates a path of travel for the vehicle to maintain thevehicle in the traffic lane in which the vehicle is traveling insituations where the lane markings demarcating the traffic lane in whichthe vehicle is traveling are not readily determinable; wherein,responsive to processing by said image processor ofimage data capturedby said camera and responsive to the location input from the globalpositioning system to said control, said control estimates the path oftravel for the vehicle to maintain the vehicle in the traffic lane inwhich the vehicle is traveling in situations where the lane markingsdemarcating the traffic lane in which the vehicle is traveling are notreadily determinable; wherein said control estimates the path of travelfor the vehicle at least responsive to vehicle information, and whereinthe vehicle information comprises at least one selected from the groupconsisting of (i) vehicle speed, (ii) vehicle differential wheel speedsand (iii) vehicle yaw rate; wherein said control estimates the path oftravel for the vehicle at least in part responsive to a location inputfrom a global positioning system to said control that provides thevehicle's current geographical location information; wherein said driverassistance system updates the estimated path of travel ahead of thevehicle even when no lane markings are determined present on the roadahead of the vehicle; wherein said control adjusts processing by saidimage processor of image data captured by said camera responsive atleast in part to a driving situation that the vehicle is in; and whereinthe driving situation comprises at least one driving situation selectedfrom the group consisting of (i) the vehicle cresting a hill, (ii) thevehicle crossing an intersection, (iii) the vehicle passing an entranceramp and (iv) the vehicle passing an exit ramp.
 10. The driverassistance system of claim 9, wherein, responsive to processing by saidimage processor of image data captured by said camera, said controlestimates the path of travel for the vehicle to maintain the vehicle inthe traffic lane in which the vehicle is traveling in situations wherethe lane markings demarcating the traffic lane in which the vehicle istraveling are lost by said camera for a period of time.
 11. The driverassistance system of claim 9, wherein, responsive to processing by saidimage processor of image data captured by said camera, said controlestimates the path of travel for the vehicle to maintain the vehicle inthe traffic lane in which the vehicle is traveling in situations wherethe lane markings demarcating the traffic lane in which the vehicle istraveling are lost by said camera as the vehicle crosses anintersection.
 12. The driver assistance system of claim 9, wherein,responsive to processing by said image processor of image data capturedby said camera, said control estimates the path of travel for thevehicle to maintain the vehicle in the traffic lane in which the vehicleis traveling in situations where lane markings are erroneouslydetermined by processing by said image processor of captured image dataalone.
 13. The driver assistance system of claim 9, wherein, responsiveto processing by said image processor of image data captured by saidcamera, said control estimates the path of travel for the vehicle tomaintain the vehicle in the traffic lane in which the vehicle istraveling in situations where processing by said image processor ofimage data alone determines lane markings that are not demarcating thetraffic lane in which the vehicle is traveling.
 14. The driverassistance system of claim 9, wherein, responsive to processing by saidimage processor of image data captured by said camera and responsive toa map input from a digital map to said control, said control estimatesthe path of travel for the vehicle to maintain the vehicle in thetraffic lane in which the vehicle is traveling in situations where thelane markings demarcating the traffic lane in which the vehicle istraveling are not readily determinable.
 15. A driver assistance systemfor a vehicle, said driver assistance system comprising: a cameradisposed at a vehicle and having a field of view forward of the vehicle;a control comprising an image processor that is operable to processimage data captured by said camera; wherein, responsive to processing bysaid image processor of image data captured by said camera, said controldetermines lane markings demarcating a traffic lane in which the vehicleis traveling; wherein, responsive to processing by said image processorof image data captured by said camera and responsive to at least oneinput selected from the group consisting of (i) a map input from adigital map to said control and (ii) a location input from a globalpositioning system to said control, said control estimates a path oftravel for the vehicle to maintain the vehicle in the traffic lane inwhich the vehicle is traveling in situations where the lane markingsdemarcating the traffic lane in which the vehicle is traveling are notreadily determinable; wherein, responsive to processing by said imageprocessor of image data captured by said camera and responsive to alocation input from a global positioning system to said control, saidcontrol estimates the path of travel for the vehicle to maintain thevehicle in the traffic lane in which the vehicle is traveling insituations where the lane markings demarcating the traffic lane in whichthe vehicle is traveling are not readily determinable; wherein saidcontrol estimates the path of travel for the vehicle at least responsiveto vehicle information, and wherein the vehicle information comprises atleast one selected from the group consisting of (i) vehicle speed, (ii)vehicle differential wheel speeds and (iii) vehicle yaw rate; whereinsaid driver assistance system updates the estimated path of travel aheadof the vehicle even when no lane markings are determined present on theroad ahead of the vehicle; wherein said control adjusts processing bysaid image processor of image data captured by said camera responsive atleast in part to a driving situation that the vehicle is in; and whereinthe driving situation comprises at least one driving situation selectedfrom the group consisting of (i) the vehicle cresting a hill, (ii) thevehicle crossing an intersection, (iii) the vehicle passing an entranceramp and (iv) the vehicle passing an exit ramp.
 16. The driverassistance system of claim 15, wherein, responsive to processing by saidimage processor of image data captured by said camera and responsive toa map input from a digital map to said control, said control estimatesthe path of travel for the vehicle to maintain the vehicle in thetraffic lane in which the vehicle is traveling in situations where thelane markings demarcating the traffic lane in which the vehicle istraveling are not readily determinable.
 17. The driver assistance systemof claim 15, wherein, responsive to processing by said image processorof image data captured by said camera, said control estimates the pathof travel for the vehicle to maintain the vehicle in the traffic lane inwhich the vehicle is traveling in situations selected from the groupconsisting of (i) situations where the lane markings demarcating thetraffic lane in which the vehicle is traveling are lost by said camerafor a period of time, (ii) situations where the lane markingsdemarcating the traffic lane in which the vehicle is traveling are lostby said camera as the vehicle crosses an intersection, (iii) situationswhere lane markings are erroneously determined by processing by saidimage processor of captured image data alone, and (iv) situations whereprocessing by said image processor of image data alone determines lanemarkings that are not demarcating the traffic lane in which the vehicleis traveling.